Recently, in the context of growing movement for environmental protection, developments of an electric vehicle (EV) and a hybrid electric vehicle (HEV) are advanced. A repeatedly-chargeable lithium-ion secondary battery draws attention as a power source for driving a motor of them.
A lithium-ion secondary battery cell is configured by stacking plural unit cells in which a separator impregnated with electrolyte is interposed between a cathode electrode and an anode electrode, and electrodes (cathode electrodes/anode electrodes) and separators are sequentially laminated in its manufacturing process.
A Patent Literature 1 listed below discloses a sheet lamination apparatus that prevents position aberration when laminating electrodes and separators. In the sheet lamination apparatus, while pressing edges of an assembled laminate composed of electrodes and separators downward by clampers, an electrodes or a separator is sequentially laminated upon the assembled laminate by a suction hand. When a new sheet member (e.g. a separator) has been laminated by the suction hand on the assembled laminate pressed downward by the clampers, the clampers are once evacuated above the new sheet member and then moved downward to press the new sheet member downward. The clampers are configures to be lifted up to a constant height level consistently. The height level is set to a constant value larger than final thickness of the assembled laminate (completed thickness) in consideration of thickness (height) increase of the assembled laminate along with progress of a lamination process.